check valve; too strong?

[barnartist]

I have filled my system, purged all the air. I cant seem to get my water moving, I even put a beefy 011 taco temporarily in place of the 007. I have studied at my plumbing scheme for hours rechecking. It all acts like a valve is closed.

Can a check valve be to strong to let the water circulate? Before I put it in it did seem a little stiff with the push of the finger. It is the only thing I can think of that can be my problem. If it werent so tough to change out I would not even ask, but its buried in threaded pipe. Curses!

Can I use a swing check instead, and what is the difference?

 

[Singed Eyebrows]

What kind of check(& brand) did you put in? All I've ever used is a Taco swing check that was problem free, Randy

 

[bigburner]

I have used a lot of both, We only in stall swing check in the horizontal and spring check in any position. Some say swing checks won't give a positive shut off to prevent thermal cycling, where a spring check will. Nice thing about a swing check is it can be cleaned or repaired if necessary.

Sounds like you got air, if it's a threaded valve then maybe some pipe dope is stuck in there- I doubt it!

remove pressure from the down stream side and pressure it upstream size garden hose. will /should flow.

I have installed dozens of these and never had one stick - "think you got air"

 

[barnartist]

it is a spring check, a threaded one from lowes.
I have air seperators on the radiant manifold. I used garden hoses to fill to system. I was able to push water with the garden hose because I could feel the cold and see it register on one of the temp valves. I followed the cold path even through the check valve as the direction of water should be allowed to go.
Both pumps I tried are working quietly and I was sure of no air in the line. I am seasoned pretty well now on how they sound when working correctly.
I feel confident air is not the issue but certainly cant rule it out completely.
As you said a swing check might allow ghost flow, is there a way to weaken the spring in the spring valve? I ran the nut as far back as I could befor I installed, it still seemed very stiff to me.

 

[Blevesque]

So you say you backed out the knurled knob on top the check valve. That should open it up. If that isn't working the likely culprit is air or a blockage in your line. Do you have kids? Could they have been down near the boiler and shoved something in the end of a open ended pipe while you were not looking? I use to do air & water balancing and we spent hours and hours and a ton of money on one job becasue a lack of water flow only to find a pepsi can stuck in a 3" to 2" reducer. I still have the can! Just a thought! Brian

 

[Hunderliggur]

You could still have air at the pump (particularly if you just changed it). My pump is on the return side of the boiler. I find I can bleed it but manually by releaseing the pressure release valve for about a gallon or so of water ( assuming you have the pressure and/or a pressure controled make up line). My air locked Taco sounds just like a working Taco - quiet.

Don't take this the wrong way, but is the circulator installed in the correct direction?

 

[NYEDGE]

I used a swing check because the less parts to go wrong the better. When I plumbed into my oil boiler, the check was holding the back pressure
for a day while I continued plumbing. Every once in a while it would "spit" through some water, but in a whole day it probably added up to about
1 - 1 1/2 cups of water. It sounds like the check might be the problem, but you don't really want the headache of taking it out. I totally understand
that, but until you do something, nothing will change. Sounds like you know your system well enough and you feel that air is not the problem, so I
would change that check to a swing and if nothing else, you'll know that's not the problem.

 

[barnartist]

Im gonna have to change out the spring check. I have ran through every senario in my mind and wile looking over every area of the plumbing.

I blew air through every line with my mouth before the install. I also have the pump going the right direction. No air in the pump, I bled it all out by opening the valves in order and cracking the pump seal. I am all to familiar with air lock, I just feel too confident in what I see to believe otherwise. I guess I was hoping to hear a majic solution or someone else that had to remove a SC.
The other issue is I live 45 min from a Plumbing store, AKA lowes, and now we have 6 inches of white stuff on the ground. Rats.

 

[in hot water]

I doubt the check valve is the problem, does it look like this? This is a fairly common "home center" valve. There are other brands, Apollo, for example.

These usually have a 1/2 psi "pop" spring in them. So the pump needs to develop 1/2 psi pressure difference to open them. That 007 has plenty of fizz to open this type of check. This valve has been used in hydronic and solar applications for many years with smaller pumps then that 007

It is possible to have air trapped in the pump, especially with a check valve right downstream from it. Maybe just carefully loosen the bolts that hold the pump into the volute, or the flange bolts and see if it burps out some air. Before you make that snowy trek :0

If the pump has isolation valves I'd remove it and make sure the shaft is not broken and that the impeller is in fact spinning.

hr

 

[Fred61]

You don't by any chance have a branch line with another check valve in it headed to another loop before the questionable check valve? I had cold water going to one of my zones and the problem turned out to be a check valve in another zone had failed (stuck open) and was bringing cold (return temperature water) back through the failing check valve and through the check valve I suspected was failing.

 

[barnartist]

Thats the valve. I got in there and took the guts out of it, put everything back and you are right it is not the problem.

I did all the pump bleeding tricks, manually purged air at every place possible. The only thing I can think of now is if I got the supply and return lines crossed, but wouldn't it still run through this manifold ok? http://cgi.ebay.com/6-Loop-Port-BRA...t-Heating-/180575109923?pt=LH_DefaultDomain_0
Or would this little device have built in check valves if I were backwards?
Just a guess, I will try and track the lines.

 

[barnartist]

You don't by any chance have a branch line with another check valve in it headed to another loop before the questionable check valve? I had cold water going to one of my zones and the problem turned out to be a check valve in another zone had failed (stuck open) and was bringing cold (return temperature water) back through the failing check valve and through the check valve I suspected was failing.

I had that happen before too Fred, but no only one in this zone.

It is still as if I had a shut off valve closed, thats how it all is behaving.

 

[in hot water]

Thats the valve. I got in there and took the guts out of it, put everything back and you are right it is not the problem.

I did all the pump bleeding tricks, manually purged air at every place possible. The only thing I can think of now is if I got the supply and return lines crossed, but wouldn't it still run through this manifold ok? http://cgi.ebay.com/6-Loop-Port-BRA...t-Heating-/180575109923?pt=LH_DefaultDomain_0
Or would this little device have built in check valves if I were backwards?
Just a guess, I will try and track the lines.

Do you have electric accuators on the manifold? Or just those plastic caps? The caps need to be screwed down on the manifold tightly, the outer part. Then the inner part needs to be opened up, counter clockwise to allow flow. I have not used that brand, but all the others work that way.

 

[barnartist]

The manifold did not come with any paperwork/instruction manual. That was the problem. The actuators were closed off preventing flow.

I will have to re install the check valve the right way. Thanks to all for the help!

 

[bigburner]

so you did have air trapped up against the closed manifold, Damn I'm good! LOL

 

[barnartist]

I had air trapped in my brain. Sure would have been nice of the manifold people to send some paperwork with the thing. At least put it up on the website.

 

[heaterman]

I had air trapped in my brain. Sure would have been nice of the manifold people to send some paperwork with the thing. At least put it up on the website.

Paperwork? Weeee done need no steeenking paperwork!

I did like this statement on their site though .... Made of High Quality Brass, not cheap Stainless Steel


LOL